28781523769 has 2 divisors, whose sum is σ = 28781523770. Its totient is φ = 28781523768.

The previous prime is 28781523751. The next prime is 28781523791. The reversal of 28781523769 is 96732518782.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28598868544 + 182655225 = 169112^2 + 13515^2 .

It is a cyclic number.

It is not a de Polignac number, because 28781523769 - 2⁵ = 28781523737 is a prime.

It is a super-2 number, since 2×28781523769² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28781503769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14390761884 + 14390761885.

It is an arithmetic number, because the mean of its divisors is an integer number (14390761885).

Almost surely, 2^28781523769 is an apocalyptic number.

It is an amenable number.

28781523769 is a deficient number, since it is larger than the sum of its proper divisors (1).

28781523769 is an equidigital number, since it uses as much as digits as its factorization.

28781523769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10160640, while the sum is 58.

The spelling of 28781523769 in words is "twenty-eight billion, seven hundred eighty-one million, five hundred twenty-three thousand, seven hundred sixty-nine".